Gas injection module, substrate processing apparatus, and method of fabricating semiconductor device using the same

ABSTRACT

A gas injection module includes a showerhead having first injection holes on a first region of the showerhead and second injection holes on a second region of the showerhead, the second region being outside the first region, a first distribution plate on the showerhead and having first and second upper passages respectively connected to the first and second injection holes, and a flow rate controller on the first and second upper passages of the first distribution plate. The flow rate controller reduces a difference in pressure within the first and second upper passages so that the gas may have similar flow rates within the first and second injection holes.

PRIORITY STATEMENT

This U.S. nonprovisional application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2018-0144454 filed on Nov. 21,2018 in the Korean Intellectual Property Office, the entire contents ofwhich are hereby incorporated by reference.

BACKGROUND

The present inventive concepts relate to apparatus and methods offabricating a semiconductor device, and more particularly, to gasinjection system or module, a substrate processing apparatus, and amethod of fabricating a semiconductor device using the same.

In general, semiconductor devices are manufactured by performing aplurality of unit processes. The unit processes may include a depositionprocess, a diffusion process, a thermal process, a photolithographyprocess, a polishing process, an etching process, an ion implantationprocess, and a cleaning process. The etching process may be a dryetching process, a wet etching process or a combination of the two. Thedry etching process may be performed in large part by plasma. Due to theplasma, a substrate may be treated at high temperature.

SUMMARY

According to one aspect of the present inventive concept, there isprovided a gas injection system comprising a showerhead having firstinjection holes in a first region of the showerhead and second injectionholes in a second region of the showerhead that is radially outwardly ofthe first region, a gas distributor on the showerhead and having firstupper passages respectively connected to the first injection holes andsecond upper passages respectively connected to the second injectionholes, and a flow rate controller configured to maintain pressure withinthe first upper passages relative to pressure in the second upperpassages such that gas, introduced into the showerhead via the gasdistributor, flows through the first injection holes at a rate similarto that at which gas flows through the second injection holes

According to another aspect of the present inventive concept, there isprovided a substrate processing apparatus comprising a chamber, a chuckin a lower portion of the chamber and dedicated to receive a substrate,and a gas injection system that provides into the chamber process gasused to process a substrate received by the chuck. The gas injectionsystem includes a showerhead in an upper portion of the chamber, a gasdistributor disposed on the showerhead, and a flow rate controller. Theshowerhead has first injection holes in a first region of the showerheadand second injection holes in a second region of the showerhead that islocated radially outwardly of the first region. The gas distributor hasfirst upper passages respectively connected to the first injection holesand second upper passages respectively connected to the second injectionholes. The flow rate controller is configured to maintain pressure ofgas within the first upper passages relative to pressure of gas withinthe second upper passages such that gas, introduced into the showerheadvia the gas distributor, flows through the first injection holes at arate similar to that at which it flows through the second injectionholes.

According to still another aspect of the present inventive concept,there is provided a gas injection module, comprising a showerhead havingfirst injection holes in a first region of the showerhead and secondinjection holes in a second region of the showerhead that is radiallyoutwardly of the first region, a gas distributor disposed on andintegral with the showerhead and having a first upper passage connectedto the first injection holes and a second upper passage discrete fromthe first upper passage and connected to the second injection holes, afirst pressure sensor in the first upper passage to detect a pressure ofgas in the first upper passage, and a second pressure sensor in thesecond upper passage to detect a pressure of gas in the second upperpassage.

According to yet another aspect of the present inventive concept, thereis provided a method of fabricating a semiconductor device, comprisingproviding a substrate on a chuck in a chamber, using a gas injectionmodule to provide a gas onto the substrate, the gas injection modulehaving in an upper portion of the chamber first passages and secondpassages outside the first passages, detecting a pressure of the gaswithin the first and second passages of the gas injection module,determining whether or not the gas has a difference in pressure withinthe first and second passages, and controlling the gas to have a similarpressure within the first and second passages when it is determined thatthe gas has the difference in pressure within the first and secondpassages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of an example of a substrate processingapparatus according to the present inventive concepts.

FIG. 2 is an exploded view, in perspective, of an example of a gasinjection module of the substrate processing apparatus shown in FIG. 1.

FIG. 3 is a plan view of an example of a showerhead of the gas injectionmodule shown in FIG. 2.

FIG. 4 is a graph showing an etch uniformity of a substrate processed bya substrate processing apparatus according to the present inventiveconcepts as shown in FIG. 1.

FIG. 5 is an exploded view, in perspective, of an example of a seconddistribution plate of the gas injection module shown in FIG. 2.

FIG. 6 is a flow chart illustrating an example of a method offabricating a semiconductor device according to the present inventiveconcepts.

DETAILED DESCRIPTION

Referring to FIG. 1, a capacitively coupled plasma (CCP) apparatus isshown as an example of a substrate processing apparatus 100 according tothe present inventive concepts may be. The substrate processingapparatus 100 may include a chamber 110, a chuck 120, a power supply130, a gas supply 140, a gas injection module 150, and a controller 160.A substrate W may be provided on the chuck 120 in the chamber 110. Thepower supply 130 may use high-frequency power 132 to create plasma 12 inthe chamber 110. The gas supply 140 may supply a gas 10 to the gasinjection module 150, which gas injection module 150 may provide the gas10 into the chamber 110. The controller 160 may control a flow rate ofthe gas 10 and the high-frequency power 132 to manage a fabricationprocess, i.e., a processing of the substrate W.

The chamber 110 may provide a hermetic space that isolates the substrateW from the environment outside the chamber. Although not shown, thechamber 110 may include a lower housing and an upper housing on thelower housing. When the lower housing is separated from the upperhousing, a robot arm may load the substrate W onto the chuck 120.

The chuck 120 may be installed in a lower portion of the chamber 110.The chuck 120 may use electrostatic voltage to hold the substrate W. Theelectrostatic voltage may be supplied through an electrostatic voltagesupply that is disposed outside the chamber 110.

The power supply 130 may be connected to the chuck 120. The power supply130 may supply the high-frequency power 132 to the chuck 120. Thehigh-frequency power 132 may excite the gas 10 on the substrate W into aplasma state. That is, the high-frequency power 132 may create a plasma12 of the gas 10.

The gas supply 140 may supply the gas 10 through the gas injectionmodule 150 to the chamber 110. For example, the gas supply 140 includesfirst gas supplies 142, a mass flow controller 144, and second gassupplies 146. The first gas supplies 142 may supply the gas injectionmodule 150 with a main constituent (e.g., Ar, N₂, or SF₆) of the gas 10.Each of the first gas supplies 142 may have a flow control valve 143.The mass flow controller 144 may be disposed between the first gassupplies 142 and the gas injection module 150. The mass flow controller144 may control a mass flow of the main gas. The second gas supplies 146may be connected to pipes 141 between the mass flow controller 144 andthe gas injection module 150. The second gas supplies 146 may have theirsubsidiary valves 145 connected to the pipes 141 between the mass flowcontroller 144 and the gas injection module 150. The second gas supplies146 may provide the gas injection module 150 with an additionalconstituent (e.g., O₂, C₄F₆, or C₄F₈) of the gas 10.

The gas injection module 150 may be installed in an upper portion of thechamber 110. The gas injection module 150 may provide the gas 10 ontothe substrate W. The gas 10 within the gas injection module 150 may havea lower pressure than that of the gas 10 within the pipes 141 betweenthe mass flow controller 144 and the gas injection module 150.

FIG. 2 illustrates an example of the gas injection module 150 shown inFIG. 1.

Referring to FIGS. 1 and 2, the gas injection module 150 may include ashowerhead 152, a first distribution plate 154, a second distributionplate 156 (or “gas distributor”), and a flow rate adjuster 158.

The showerhead 152 may include a plurality of injection holes 30. Thegas 10 may be sprayed onto the substrate W through the injection holes30. Each of the injection holes 30 may have a diameter of about 0.5 mmto about 1 mm. When the showerhead 152 is initially used, the injectionholes 30 may have the same size (e.g., diameter). In addition, the gas10 may have similar flow rates within the injection holes 30. Thearrangement of the injection holes 30 may correspond to the shape of thesubstrate W. For example, when the substrate W is circular, theinjection holes 30 may be arranged (laid out) along a series ofconcentric circles. The showerhead 152 may have regions, e.g., a firstregion 22 and a second region 24, associated with corresponding regionsof the substrate W. The first region 22 may correspond to a centralregion C of the substrate W, and the second region 24 may correspond toan edge (outer peripheral) region E of the substrate W. The first region22 may include a central portion 21 and a middle portion 23 of theshowerhead 152. The second region 24 may be disposed outside or aroundthe first region 22. The second region 24 may include an a radiallyouter portion 25 and a radially outermost portion 27 of the showerhead152. The injection holes 30 may be regularly and evenly arranged in thefirst and second regions 22 and 24. The injection holes 30 may include,for example, first injection holes 32 and second injection holes 34disposed in the first region 22 and second injection holes 34 disposedin the second region 24.

The first injection holes 32 may include central injection holes 31 andmiddle injection holes 33. The central injection holes 31 may bearranged along several rings. For example, a number (e.g., 4) of thecentral injection holes 31 may be arranged along a first ring, a number(e.g., 12) of the central injection holes 31 second ring, and a number(e.g., 24) of the central injection holes 31 may be arranged along athird ring. The middle injection holes 33 may be disposed outside oraround the central injection holes 31. The middle injection holes 33 mayinclude a number (e.g., 36) of holes arranged along a fourth ring, anumber (e.g., 48) of holes arranged along a fifth ring, and a number(e.g., 60) of holes arranged along a sixth ring.

The second injection holes 34 may be disposed outside or around themiddle injection holes 33. The second injection holes 34 may includeradially outer injection holes 35 and radially outermost injection holes37. The radially outer injection holes 35 (e.g., 80 holes) may bearranged along a seventh ring. The radially outermost injection holes 37may be disposed outside or around the radially outer injection holes 35.The radially outermost injection holes 37 (e.g., 100 holes) may bearranged along an eighth ring.

FIG. 3 illustrates an example of the showerhead 152 shown in FIG. 2.

Referring to FIGS. 1 and 3, because the plasma 12 has a greater densityon the central region 21 than on the second region 24 of the showerhead152, the plasma 12 may cause the first injection holes 32 to expand andbecome wider. Thus, when the showerhead 152 is used for a certain amountof time, the first injection holes 32 can become bigger than the secondinjection holes 34. In other cases the second injection holes 34 maybecome bigger than the first injection holes 32. That is, use of theshowerhead 152 may create a difference in size between the first andsecond injection holes 32 and 34. When the difference in size occursbetween the first injection holes 32 and the second injection holes 34,the gas 10 within the first and second injection holes 32 and 34 mayhave different flow rates. When the gas 10 travels at different flowrates within the first and second injection holes 32 and 34, the etchuniformity of the substrate W may be compromised.

FIG. 4 illustrates an etch uniformity of the substrate W when processedusing the apparatus shown in FIG. 1.

Referring to FIG. 4, when the first injection holes 32 become biggerthan the second injection holes 34, the outer peripheral region E of thesubstrate W may be etched to a greater extent than the central region C.This may be caused by the gas 10 within the first injection holes 32traveling at a flow rate less than that of the gas 10 within the secondinjection holes 34. This may also be caused due to a difference inpressure of the gas 10 in the first and second injection holes 32 and34.

Mechanisms and techniques of controlling the gas 10 to have similarpressures and/or flow rates within the gas injection module 150, with anaim towards maximizing etch uniformity of the substrate W according toan aspect of the inventive concept, will now be described in detail.Here, and in the description that follows, the term “similar” is used tomean the same and yet account for any minor differences within apredetermined allowable margin of error given the level of precisionthat can be provided by elements of a flow controller as will bedescribed below in more detail.

Referring back to FIG. 2, the first distribution plate 154 may bedisposed on the showerhead 152. The first distribution plate 154 mayhave a plurality of lower passages 40. The lower passages 40 may beconnected to the injection holes 30. The gas 10 may be provided throughthe lower passages 40 to the injection holes 30. For example, the lowerpassages 40 may have the shape of concentric circles. The lower passages40 may include lower grooves 46 and lower holes 48 open to the lowergrooves 46 at the bottom of the lower grooves 46. The lower holes 48 maybe aligned with the injection holes 30. The lower grooves 46 may bedisposed directly on the injection holes 30.

The lower grooves 46 may include first lower grooves 42 and second lowergrooves 44. The first lower grooves 42 may be disposed on the firstinjection holes 32. The first lower grooves 42 may include lower centralgrooves 41 and lower middle grooves 43. The second lower grooves 44 maybe disposed outside or around the first lower grooves 42. The secondlower grooves 44 may include a lower radially outer groove 45 and alower radially outermost groove 47.

The second distribution plate 156 may be disposed on the firstdistribution plate 154. The second distribution plate 156 may have aplurality of upper passages 50. The upper passages 50 may be connectedto, i.e., in open communication with, the lower passages 40. The gas 10may be provided through the upper passages 50 to the lower passages 40.

The upper passages 50 may include first upper passages 52 and secondupper passages 54. The first upper passages 52 may be disposed in thefirst region 22. The first upper passages 52 may include an uppercentral passage 51 and an upper middle passage 53. The upper centralpassage 51 may be disposed in the central region 21. The upper middlepassage 53 may be disposed in the middle region 23. The second upperpassages 54 may be disposed outside or around the first upper passages52. The second upper passages 54 may include an upper radially outerpassage 55 and an upper radially outermost passage 57. The upperradially outer 55 may be disposed in the radially outer region 25, andthe upper radially outermost passage 57 may be disposed in the radiallyoutermost region 27.

FIG. 5 illustrates an example of the second distribution plate 156 shownin FIG. 2.

Referring to FIG. 5, the second distribution plate 156 may include alower plate 155, an intermediate plate 157, and an upper plate 159.

Referring to FIGS. 2 and 5, the lower plate 155 may be disposed on thefirst distribution plate 154. The lower plate 155 may include lowerholes 60. The lower holes 60 may be connected to the lower passages 40.The lower holes 60 may include first lower holes 62 and second lowerholes 64. The first lower holes 62 may be disposed in the first region22, and the second lower holes 64 may be disposed in the second region24. The first lower holes 62 may include lower central holes 61 andlower middle holes 63. The lower central holes 61 may be disposed in thecentral region 21, and the lower middle holes 63 may be disposed in themiddle region 23. The second lower holes 64 may be disposed outside oraround the first lower holes 62. The second lower holes 64 may includelower radially outer holes 65 and lower radially outermost holes 67. Thelower radially outer holes 65 may be disposed in the radially outerregion 25. The lower radially outermost holes 67 may be disposed in theradially outermost region 27.

The intermediate plate 157 may be disposed on the lower plate 155. Theintermediate plate 157 may include intermediate holes 70. Theintermediate holes 70 may be connected to the lower holes 60. Theintermediate holes 70 may include first intermediate holes 72 and secondintermediate holes 74. The first intermediate holes 72 may be disposedin the first region 22, and the second intermediate holes 74 may bedisposed in the second region 24. The first intermediate holes 72 mayinclude intermediate central holes 71 and intermediate middle holes 73.The intermediate central holes 71 may be disposed in the central region21, and the intermediate middle holes 73 may be disposed in the middleregion 23. The second intermediate holes 74 may be disposed outside oraround the first intermediate holes 72. The second intermediate holes 74may include intermediate radially outer holes 75 and intermediateradially outermost holes 77. The intermediate radially outer holes 75may be disposed in the radially outer region 25, and the intermediateradially outermost holes 77 may be disposed in the radially outermostregion 27.

The upper plate 159 may be disposed on the intermediate plate 157. Theupper plate 159 may include upper grooves 80 and introduction holes 90on the upper grooves 80.

The upper grooves 80 may be connected to the intermediate holes 70. Theupper grooves 80 may have the shape of concentric circles. The uppergrooves 80 may include first upper grooves 82 and second upper grooves84. The first and second upper grooves 82 and 84 may be respectivelydisposed in the first and second regions 22 and 24. The first uppergrooves 82 may include an upper central groove 81 and an upper middlegroove 83. The upper central groove 81 may be disposed in the centralregion 21, and the upper middle groove 83 may be disposed in the middleregion 23. The second upper grooves 84 may be disposed outside or aroundthe first upper grooves 82. The second upper grooves 84 may include anupper radially outer groove 85 and an upper radially outermost groove87. The upper radially outer groove 85 may be disposed in the radiallyouter region 25, and the upper radially outermost groove 87 may bedisposed in the radially outermost region 27.

The introduction holes 90 may be connected to the pipes 141 of the massflow controller 144 shown in FIG. 1. The introduction holes 90 mayinclude first introduction holes 92 and second introduction holes 94.The first introduction holes 92 may be connected to the first uppergrooves 82. The first introduction holes 92 may include a centralintroduction hole 91 and a middle introduction hole 93. The centralintroduction hole 91 may be connected to the upper central groove 81.The middle introduction hole 93 may be connected to the upper middlegroove 83. The second introduction holes 94 may be disposed outside oraround the first introduction holes 92. The second introduction holes 94may include a radially outer introduction hole 95 and a radiallyoutermost introduction hole 97. The radially outer introduction hole 95may be connected to the upper radially outer groove 85. The radiallyoutermost introduction hole 97 may be connected to the upper radiallyoutermost groove 87.

Referring to FIGS. 1, 2, and 5, the flow rate adjuster 158 may detectpressure of the gas 10 within the first upper passages 52 and the secondupper passages 54 of the second distribution plate 156. Based on thedetected pressure, the flow rate adjuster 158 may reduce a difference inpressure between the gas 10 within the first upper passages 52 and thegas 10 within the second upper passages 54, such that the gas 10 hassimilar (the same or substantially the same) flow rates within the firstand second injection holes 32 and 34. For example, the flow rateadjuster 158 may include pressure sensors 170, lower valves 180, andupper valves 190. Controller 160 together with the flow rate adjuster158 (pressure sensors 170 and lower and/or upper valves 180 and 190, forexample) may constitute a flow rate controller of a gas injection systemaccording to the inventive concept.

The pressure sensors 170 may be installed in the upper grooves 80 and,in particular, on surfaces defining the sides of the upper grooves 80.The pressure sensors 170 may detect a pressure of the gas 10 within theupper grooves 80.

The pressure sensors 170 may include first pressure sensors 172 andsecond pressure sensors 174. The first pressure sensors 172 may bedisposed in the first upper grooves 82, and may detect a pressure of thegas 10 within the first upper grooves 82. The first pressure sensors 172may include a central sensor 171 and a middle sensor 173. The centralsensor 171 may be disposed in the upper central groove 81, and maydetect a pressure of the gas 10 within the upper central groove 81. Themiddle sensor 173 may be disposed in the upper middle groove 83, and maydetect a pressure of the gas 10 within the upper middle groove 83.

The second pressure sensors 174 may be disposed in the second uppergrooves 84, and may detect a pressure of the gas 10 within the secondupper grooves 84. The second pressure sensors 174 may include a radiallyouter sensor 175 and a radially outermost sensor 177. The radially outersensor 175 may be disposed in the upper radially outer groove 85, andmay detect a pressure of the gas 10 within the upper radially outergroove 85. The radially outermost sensor 177 may be disposed in theupper radially outermost groove 87, and may detect a pressure of the gas10 within the upper radially outermost groove 87.

The lower valves 180 may be installed below the pressure sensors 170.For example, the lower valves 180 may be disposed in the lower holes 60,respectively. The lower valves 180 may control the flow rates of the gas10 within the lower holes 60. For example, the lower valves 180 may beorifice valves, i.e., valves that have an orifice whose size (diameteror width) is adjustable. When the lower valves 180 open (e.g., whenorifices of the lower valves 180 become wider), the flow rate of gas 10within the lower holes 60 increases. When the lower valves 180 close(e.g., when orifices of the lower valves 180 become narrower), the flowrate of gas 10 within the lower holes 60 decreases.

The lower valves 180 may include first lower valves 182 and second lowervalves 184. The first lower valves 182 may be disposed in the firstlower holes 62, and may control the flow rate of the gas 10 within thefirst lower holes 62. The first lower valves 182 may include lowercentral valves 181 and lower middle valves 183. The lower central valves181 may be disposed in the lower central holes 61, and may control theflow rate of the gas 10 within the lower central holes 61. The lowermiddle valves 183 may be disposed in the lower middle holes 63, and maycontrol the flow rate of the gas 10 within the lower middle holes 63.The second lower valves 184 may be disposed in the second lower holes64, and may control the flow rate of the gas 10 within the second lowerholes 64.

The second lower valves 184 may include lower radially outer valves 185and lower radially outermost valves 187. The lower radially outer valves185 may be disposed in the lower radially outer holes 65, and maycontrol the flow rate of the gas 10 within the lower radially outerholes 65. The lower radially outermost valves 187 may be disposed in thelower radially outermost holes 67, and may control the flow rate of thegas 10 within the lower radially outermost holes 67.

The upper valves 190 may be installed above the pressure sensors 170.For example, the upper valves 190 may be connected between the mass flowcontroller 144 and the introduction holes 90 of the upper plate 159. Theupper valves 190 may be orifice valves.

The upper valves 190 may include first upper valves 192 and second uppervalves 194. The first upper valves 192 may be connected to (i.e., may bedisposed in-line with) the first introduction holes 92, and may controlthe flow rate of the gas 10 within the first introduction holes 92. Thefirst upper valves 192 may include an upper central valve 191 and anupper middle valve 193. The upper central valve 191 may be connected tothe central introduction hole 91, and may control the flow rate of thegas 10 within the central introduction hole 91. The upper middle valve193 may be connected to the middle introduction hole 93, and may controlthe flow rate of the gas 10 within the middle introduction hole 93. Thesecond upper valves 194 may be connected to the second introductionholes 94, and may control the flow rate of the gas 10 within the secondintroduction holes 94. The second upper valves 194 may include an upperradially outer valve 195 and an upper radially outermost valve 197. Theupper radially outer valve 195 may be connected to the radially outerintroduction hole 95, and may control the flow rate of the gas 10 withinthe radially outer introduction hole 95. The upper radially outermostvalve 197 may be connected to the radially outermost introduction hole97, and may control the flow rate of the gas 10 within the radiallyoutermost introduction hole 97.

The controller 160 may be connected to the pressure sensors 170, thelower valves 180, and the upper valves 190. The controller 160 mayreceive information of the pressures of the gas 10 within the uppergrooves 80, may compare the pressures of the gas 10 with each other, andbased on the compared pressures, may control the flow rate of the gas10. To this end, the controller 160 may include a pressure signaldetector 162, a comparator 164, and a valve controller 166. As istraditional in the field of controllers related to the inventiveconcepts, the blocks of the controller 160, e.g., the pressure signaldetector 162, comparator 164, valve controller 166, may be physicallyimplemented by analog and/or digital circuits. The circuits constitutinga block may be implemented by dedicated hardware, by one or moreprogrammed processors (e.g., microprocessor(s)) and associatedcircuitry, or by a combination of dedicated hardware to perform somefunctions of the block and a processor to perform other functions of theblock.

The detector 162 may be connected to the pressure sensors 170 so as toreceive signals from the pressure sensors 170, i.e., to receiveinformation of the pressures of the gas 10 within the gas injectionmodule 150 as sensed by the pressure sensors 170. The detector 162 mayconvert the output of the pressure sensors 170 into signalsrepresentative of the values of pressures of the gas 10 within the gasinjection module 150.

The comparator 164 may compare the signals generated by the detector162. Based on the compared signals, the comparator 164 may determinewhether the size of any or certain ones of the injection holes 30 haschanged to such an extent that a difference in size exists betweenrespective ones of the injection holes 30.

The valve controller 166 may control the lower valves 180 and the uppervalves 190 in such a manner that the gas 10 has similar (the same orsubstantially the same) pressures within respective regions of the gasinjection module 150. Likewise, the valve controller 166 may beconfigured to control the lower valves 180 and the upper valves 190 insuch a manner that the gas 10 flows at similar rates within respectiveregions of the gas injection module 150.

For example, when the comparator 164 determines that the pressure of thegas 10 in the first region 22 is lower than that of the gas 10 in thesecond region 24, the valve controller 166 may control the first uppervalves 192 to open wider than the second upper valves 194. When thefirst upper valves 192 are controlled to open wider than the secondupper valves 194, the pressure of gas 10 in in the first region 22increases. When the pressure of the gas 10 in the first region 22increases, the pressure of the gas 10 in the first and second regions 22and 24 may equalize, i.e., become similar. In addition, the gas 10 mayflow at similar rates within the first and second injection holes 32 and34. Accordingly, the substrate W may be processed uniformly across thesurface thereof, e.g., the etch uniformity of a process of etching thesubstrate W may be high.

When the comparator 164 determines that the pressure of the gas 10 inthe first region 22 is lower than that of the gas 10 in the secondregion 24, the flow rate controller 166 may control the second lowervalves 184 of the second region 24 to close to a greater extent than thefirst lower valves 182 of the first region 22. In this case the pressureof the gas 10 in the second region 24 is reduced. Accordingly, thepressures of the gas 10 in the first and second regions 22 and 24 mayequalize and become similar pressure. Likewise, the rates at which thegas 10 flows within the first and second injection holes 32 and 34 maybecome similar.

An example of a method of processing a substrate in the fabricating of asemiconductor device according to the present inventive concepts willnow be described with reference to FIGS. 1 and 6.

Referring to FIGS. 1 and 6, a method of fabricating a semiconductordevice according to the present inventive concepts may include providingthe substrate W (S100), providing the gas 10 (S200), detecting apressure of the gas 10 within the gas injection module 150 (S300),determining whether a difference in pressure exists among differentregions of the gas 10 (S400), and controlling the gas 10 such that thedifferent regions of the gas have similar (the same or substantially thesame) pressures (S500).

A robot arm (not shown) may load the substrate W onto the chuck 120 in aprocessing space of the chamber 110 (S100).

The gas injection module 150 may provide the gas 10 to a processingspace within the chamber 110 (S200). The power supply 130 may supply thehigh-frequency power 132 to create the plasma 12. The plasma 12 may etchthe substrate W. Alternatively, a thin layer may be deposited on thesubstrate W using the plasma 12.

The detection controller 162 may use the pressure sensors 170 to detecta pressure of the gas 10 within the gas injection module 150 (S300).

The pressure comparison controller 164 may compare pressures of the gas10 within different regions of the gas injection module 150 to determinewhether a difference in gas pressure exists within respective regions ofthe gas injection module 150 (S400). When there is no pressuredifference in the gas 10 among the respective regions of the gasinjection module 150, no action is taken. However, the detectioncontroller 162 may continue to periodically detect the pressure of thegas 10 within the respective regions of the gas injection module 150(S300).

On the other hand, when a difference in gas pressure is detected, theflow rate controller 166 controls the lower valves 180 and the uppervalves 190 to equalize the pressure of the gas 10 within the gasinjection module 150 (S500).

According to the present inventive concepts, a gas injection module hasa flow rate controller that reduces a difference in pressure resultingfrom a difference in size of injection holes between central and outerperipheral areas of a showerhead, with the result that a substrate maybe processed (etched or have a thin film formed thereon) uniformly.

Although the present inventive concepts have been described inconnection with the examples illustrated in the accompanying drawings,it will be understood to those skilled in the art that various changesand modifications may be made to such examples without departing fromthe technical spirit and scope of the present inventive concepts. Ittherefore will be understood that the examples described above are justillustrative but not limitative in all aspects of the inventive conceptas defined by the appended claims.

What is claimed is:
 1. A gas injection system, comprising: a showerheadhaving first injection holes in a first region of the showerhead andsecond injection holes in a second region of the showerhead, the secondregion being radially outwardly of the first region; a gas distributorabove the showerhead and having first upper passages respectivelyconnected to the first injection holes and second upper passagesrespectively connected to the second injection holes; and a flow ratecontroller configured to maintain pressure within the first upperpassages relative to pressure in the second upper passages such thatgas, introduced into the showerhead via the gas distributor, flowsthrough the first injection holes at a rate similar to that at which gasflows through the second injection holes, wherein the flow ratecontroller includes first pressure sensors disposed in the first upperpassages, respectively, and second pressure sensors disposed in thesecond upper passages, respectively, to detect pressures of the gaswithin the first upper passages and the second upper passages, andwherein the gas distributor includes a lower plate having first lowerholes connected to the first injection holes and second lower holesconnected to the second injection holes, and an upper plate having firstgrooves overlying the first lower holes and second grooves overlying thesecond lower holes, wherein the first pressure sensors are disposed inthe first grooves and the second pressure sensors are disposed in thesecond grooves.
 2. The gas injection system of claim 1, wherein the flowrate controller further includes first lower valves in the first lowerholes below the first pressure sensors, and second lower valves in thesecond lower holes below the second pressure sensors.
 3. The gasinjection system of claim 1, wherein the upper plate further has firstintroduction holes on the first grooves and second introduction holes onthe second grooves.
 4. The gas injection system of claim 3, wherein theflow rate controller further includes first upper valves connected tothe first introduction holes and disposed above the first pressuresensors, and second upper valves connected to the second introductionholes and disposed above the second pressure sensors.
 5. The gasinjection system of claim 1, wherein the gas distributor furtherincludes an intermediate plate having first intermediate holes extendingbetween the first injection holes and the first grooves, and secondintermediate holes extending between the second injection holes and thesecond grooves.
 6. The gas injection system of claim 1, wherein thefirst region has a central section and a middle section radiallyoutwardly of the central section, and the first pressure sensors includea central sensor in the central section and a middle sensor in themiddle section.
 7. The gas injection system of claim 1, wherein thesecond region of the showerhead has a radially outer part and a radiallyoutermost part radially outwardly of the radially outer part, and thesecond pressure sensors include a radially outer pressure sensor in theradially outer part of the second region of the showerhead and aradially outermost pressure sensor in the radially outermost part of thesecond region of the showerhead.
 8. The gas injection system of claim 1,further comprising a distribution plate interposed between theshowerhead and the gas distributor, wherein the distribution plate hasfirst lower passages extending between the first injection holes and thefirst upper passages, and second lower passages extending between thesecond injection holes and the second upper passages.
 9. A gas injectionmodule, comprising: a showerhead having first injection holes in a firstregion of the showerhead and second injection holes in a second regionof the showerhead, the second region being radially outwardly of thefirst region; a gas distributor disposed above and integral with theshowerhead, the gas distributor having a first upper passage connectedto the first injection holes, and a second upper passage discrete fromthe first upper passage and connected to the second injection holes; afirst pressure sensor in the first upper passage to detect a pressure ofgas in the first upper passage; and a second pressure sensor in thesecond upper passage to detect a pressure of gas in the second upperpassage, wherein the gas distributor includes a lower plate having firstlower holes extending therethrough and open to the first injectionholes, respectively, and second lower holes extending therethrough andopen to the second injection holes, respectively, and an upper platehaving a first annular groove in an upper surface thereof and a secondannular groove in the upper surface and disposed radially outwardly ofthe first annular groove, the first annular groove overlying and open tothe first lower holes, and the second annular groove overlying and opento the second lower holes, wherein the first annular groove and thefirst injection holes constitute the first upper passage, the secondannular groove and the second injections holes constitute the secondupper passage, the first pressure sensor is disposed in the firstannular groove and the second pressure sensor is disposed in the secondannular groove.
 10. The gas injection module of claim 9, furthercomprising: valves disposed in sections of the first upper passage andthe second upper passage of the gas distributor, respectively and eachoperable to selectively constrict and expand a respective one of saidsections.
 11. The gas injection module of claim 9, further comprising:first valves in the first lower holes, respectively, and each operableto selectively constrict and expand a respective one of the first lowerholes; and second valves in the second lower holes, respectively, andeach operable to selectively constrict and expand a respective one ofthe second lower holes.
 12. A gas injection system comprising the gasinjection module as claimed in claim 10, further comprising: a pressuresignal detector connected to the first pressure sensor and the secondpressure sensor and operative to convert outputs of the first and secondpressure sensors into signals representative of values of pressures ofgas within the first upper passage and the second upper passage,respectively, and a comparator operatively connected to the pressuresignal detector and configured to compare a value of pressure of the gaswithin the first upper passage with a value of pressure of the gaswithin the second upper passage; and a valve controller operativelyconnected to the comparator and the valves so as to control the valvesbased on a comparison of the pressures by the comparator.